"""This test cross-checks our implementation of CODATA against the
implementation that SCIPY brings with it.
"""


def test_units():
    import numpy as np
    from ase.units import CODATA
    import scipy.constants.codata

    name_map = {'_c': 'speed of light in vacuum',
                '_mu0': 'mag. const.',
                '_Grav': 'Newtonian constant of gravitation',
                '_hplanck': 'Planck constant',
                '_e': 'elementary charge',
                '_me': 'electron mass',
                '_mp': 'proton mass',
                '_Nav': 'Avogadro constant',
                '_k': 'Boltzmann constant',
                '_amu': 'atomic mass unit-kilogram relationship'}

    for version in sorted(CODATA.keys()):
        print('Checking CODATA version "{0}"'.format(version))

        try:
            scipy_CODATA = getattr(scipy.constants.codata,
                                   '_physical_constants_{0}'.format(version))
        except AttributeError:
            print('\tNot available through scipy, skipping')
            continue

        for unit, scipyname in name_map.items():
            aseval = CODATA[version][unit]
            try:
                scipyval = scipy_CODATA[name_map[unit]][0]
                msg = 'Unit "{0}" : '.format(name_map[unit])
                ok = True
                if np.isclose(aseval, scipyval):
                    msg += '[OK]'
                else:
                    msg += '[FALSE]'
                    ok = False
                print('\t' + msg)
                if not ok:
                    raise AssertionError

            except KeyError:
                # 2002 in scipy contains too little data
                continue


test_units()